1. Field Technology
This invention relates to a feed or retrieve device for use in apparatus for automatic mounting of electric parts on a sheet board.
This invention provides a particularly high practical value as a feeding or retrieving device having a highly efficient automatic mechanism for feeding and retrieving sheet boards such as, for instance, printed circuit boards, in an apparatus for automatically and sequentially inserting lead wires of electric parts such as, for instance, ceramic capacitors, film capacitors, electrolytic capacitors, various types of resistors etc. into specified holes on the printed circuit boards, etc.
2. Prior Art
An automatic feeding and retrieving device of this kind in the prior art is shown in FIG. 1, wherein a body 1 of the device comes down to separate with its claws 2 and 2' a stock of printed circuit boards stacked at a feeding part A and to pick therefrom the boards one by one and, holding one board between the claws, goes upward and then sideways to carry said board to a processing part B, where said body comes down again and releases said printed circuit board. Then said body 1 goes upward and returns sideways above the feeding part A. This movement is sequentially repeated. Synchronously with the movement of the claws 2 and 2' during this operation, claws 3 and 3' retrieve said printed circuit board already processed from the processing position and carry it to a box 4 to release thereinto. Such repetition was the automatic feeding and retrieving procedure of the prior art. Numerals 5 and 6 are cylinders for carrying sideways and for up-and-down movement, respectively.
In this prior art device, the structural construction is necessarily complicated because of the mechanism of separating, picking, holding, carrying and releasing the printed circuit boards, and also there is a danger of the boards being scratched or scraped off when gripped by the claws. Moreover, there are such shortcomings that when each printed circuit board is, after processing, dropped into the retrieve case 4, installed electric parts are liable to loosening or shaking-off, that a cylinder having a working stroke to cover its lateral movement as well as an open space sufficient therefor are required, that it is difficult to place around the processing part B such processing devices as an insertion head for planting parts onto the printed circuit boards at the processing place B since the body 1 of the device travels over the processing place B, and like inconveniences.
There is another type of prior art (as seen in U.S. Pat. No. 3,364,723) which is designed to suck up and carry the sheet board with a sucking disk. In this case, although there is no danger for the sheet board to be damaged while being lifted, it is difficult for sheet boards already planted with electric parts or materials to be stacked up at the feeding part for automatic sequential feeding. There is also the same inconvenience of placing around the processing part B such a large device as an insertion head like in the preceding case.
There is still another type of prior art (as seen in U.S. Pat. No. 3,789,483) designed to feed sheet boards to the processing part by a rotary unit. In this device however, the mechanism for rotating with sheet boards on it is complicated and is not suitable for speeding up the insertion of electric parts and also not suitable as a feeding and retrieving device for sequential combination with two or more inserting machines.